1. Field of the Invention
This invention relates to coating applicators or, dispensers, such as for the application of typewriter white-out, coloring, cosmetics for make-up, anti-perspirants, deodorants, medications, touch-ups, swabs, polish to shoes, etc. They can dispense liquids, particles or micro-capsules in suspension. The applicator or dispenser has a shaped open pore wicking nib for controllably transferring fluid coating material to the surface of an object to be coated. Because of the relative stability of the nib, small or narrow areas can be coated even though they are adjacent areas that are not to be coated or that are, for example, of different colors.
2. Description of Related Art
Present coating applicators, such as brush type typewriter white-out, felt type and capillary type markers and shoe polish applicators, etc., are designed for cover-up, marking and the care of shoes that are of one color. They are designed to yield so that curved surfaces and hard to reach areas can be contacted by the readily deformable wicking pad. The applicator of the patent issued 15 Sep. 1964 to J. R. Gilchrist et al., U.S. Pat. No. 3,148,401, is representative of the type that have a soft, readily deformable foam or fabric pad for wicking the liquid polish from a supply container and spreading the polish onto a surface such as a shoe. The pads are generally made of a polyurethane or other sponge with a large open cell configuration or of a felt material. When pressed against a shoe to release the polish, the pad surface engages the shoe and deforms so that its shape and dimensions are significantly altered to conform to the shape of the surface area being coated.
A problem with liquid applicators using soft foam wicking application pads is that the compacted foam often becomes so thin that its wicking characteristics are significantly altered; the compressed foam often becomes permanently compacted; and as the liquid of the polish dries and solidifies in the pad, the pad becomes a hardened mass that is incapable of conforming to the contours of the shoe. Frequently, on hardening, the pad clogs and will no longer permit the passage of the coating material or polish. Another problem is that soft foam is prone to being worn or scraped off during use. This usually results in an uneven application or puddling of the coating on the surface. When multi-color shoes or other surfaces with irregular patterns are coated, adjacent surface areas are routinely inadvertently coated also.
Nib pens are quite popular. The use of white color nib dispensers has not been as popular because they are not as effective as other color dispensers. Liquid coatings and solid films having white pigments and frangible white films are routinely used to coat or cover over smudges and mistakes such as typing errors. The liquid coatings are typically applied by a brush means and solid films are typically applied by impacting a carrier to transfer a frangible white film on the carrier. The pigmented liquids are routinely stored in containers that are closed by a threaded cap that is attached to the brush or applicator. The removal of the cap to use the applicator admits air into the container and the air ultimately results in the premature solidification of the pigmented liquid within the container. This problem is similar to that experienced with some shoe polish applicators. Also, the brush applicators do not permit controlled dispensing of the width nor the location of application desired. The pigmented films are difficult to position and usually require the same key to be used to correct the error that was used to make the error. The primary reason white nib pens have not been used with pigmented materials is that the carriers dry out and the pigments clog the small or porous passageways. It has unexpectedly been discovered that a small pore compressed foam can be used to dispense a pigment containing liquid. In view of this, pigmented liquid coating materials can be dispensed through a narrow porous shaped nib. By use of the appropriate pigment carrier, it has unexpectedly been found that the nib will neither clog nor permanently dry out.
U.S. Pat. No. 4,925,327, issued 15 May 1990 to D. Wirt, teaches a liquid applicator with a supply and open cell elastomer foam sponge. The foam is given a permanent compression set with a reduction in its original volume of from 1.5 to 10. A reduction in volume of 1/2to 1/4its original volume is preferred. The sponge has from 10 to 100 pores per linear inch with 90 pores per inch preferred. A layer of porous unfoamed material is used to meter the liquid from the supply to the sponge applicator. The combination is designed or selected so that the liquid will wet but not drip, the storage capacity (density) of the sponge will be regulated to hold the amount of liquid to be dispensed, and to control or adjust the viscosity and the surface tension of the liquid to be dispensed.
The use of nib dispensers is common in the art. The dispensers are used for marking, cosmetics, medications, etc. The nibs are commonly made from felt, fibers and extrusions. some nibs have been made by sintering or foaming. The word "foam" is frequently misused. It is often used as a substitute for the generic word "porous."
Foams have been in use to dispense solid particles for some time. Zimmerman, U.S. Pat. No. 2,204,263, issued 11 Jun. 1940, is one example of a powder cosmetic applicator. Porous nibs made by sintering are taught by Casey et al, U.S. Pat. No. 3,628,876, issued 21 Dec. 1971, and Dickey et al, U.S. Pat. No. 3,942,903, issued 9 Mar. 1976. The nibs can be made hard to resist wear with Jones, U.S. Pat. No. 3,881,828, issued 6 May 1975, one example. Lundsager, U.S. Pat. No. 3,449,954, issued 10 Jun. 1969, teaches the use of a fine foam. It is well known that a sheath, repellant coating casing, covering or sleeve can be used over a thin or frangible nib to lend support and that the reservoir can be provided with a porous ink saturated tampon, fibers, wick or absorbant core material with U.S. Pat. No. 4,408,921, issued 11 Oct. 1983, an example. Reservoirs are generally formed from a plastic, metal or other material into a fluid container. The nib is sealed within an opening in the container with evaporation prevented by a friction fit, snap fit, or threaded cap. Foams in general are discussed further in applicant's aforementioned parent, U. S. Pat. No. 5,299,877, issued 15 April 1994.
There has been a general assumption that large pores were necessary to conduct the coating, and in particular a pigment containing coating material, through a porous applicator pad. Even with the use of large pores, there has been a problem with the pads hardening and preventing the free flow of the coating material through the pad.